Electron discharge tube



June 11, 1935. 1 F. D. GOODCHILDET AL' 2,004,605

ELECTRON DISCHARGE TUBE Filed May 4, 1933 INVENTORS FD. GOODCH/LD W. E. BENHAM A TTORNEV Patented June 11, 1935 iii" Umrso starts raj-TEEN o i fi 7 i 2,004,605 ELECTRON DISCHARGE TUBE v Frank 1). Goodchild and Wilfrid E. Benham, Al dwych, London, England, assignors to Western Electric Company, Incorporated, New 'York, N. Y., a corporation'of New york j Application ll/lle'ty L-1933, Serial'No. 669,320 In Great Britain May 6,1932- 4 Claims. -(cl. 250-275) This invention relates to improvements in and The invention is more, particularly described relating to electron discharge tubes, and more W th refe ce to-thea c p iy drawing nv Particularly to an electrode structure for such which: tubes. v "Fig. 1 shows'the component parts and method 5 One'object of this invention is to provide'a of assembly, of a triode accordingto the present 5 complete electrode structure for an electron disinvention, and 9 charge tube; comprising-for example, a'cathode,- Fig. 2 shows the completed structure. a'control electrode or grid andan anode,"which- The dischargetube in the-embodiment of the can beassembled as a single unit and subse invention-"shown fis ofthetype described and- 1'6 quently mounted on the pinch of the tube, comclaimed in our British Patent No. 360,433 in 0 plete and ready for insertion in the bulb of the which bothzthe grid and anode are provided with, tube. Q cooling fins of considerable areain proportion 1 This method of construction is particularly to the area of the grid and anode structure. In v advantageous in the case of tubes in'whichthe the'case, for example,:of a three-electrode tube, inter-electrode distances .arevery small;- In the'anode': may be. splitlto permit-the passage, 15

such tubes, asmall variation in" the. electrode of thegrid'cooling .fin, the grid and anode coolspacing will cause a considerable changein the i'ngzfins being .generallysarranged irf-thex-same. characteristics of the'tube. :Hence,whensuch plane. .5. j I tubes have to bemanufactured by the methods 1 'Inthe embodiment of the invention shown in of mass production, it is essential that uniformity th.edrawing, theigrid electrode :l, which may be 20 be obtained between one tube'and the .next, or of'thet'ype describedkand claimed'in: our' British otherwise the characteristics of different .tube's Patent'No'. 36'9,'21'7,'surrounds' an indirectly heated will show undesirable variations. cathode'ziand is provided"with-a cooling finij3. A further object of thisinvention i's'ito provide The anode' lin turnsurroun'ds the grid and is split. a rigid assembly-of the electrodes]. This is also to permit the passage of-the grid cooling fin 3."

particularly important when the. inter-electrode The anode is provided with a cooling fin 6. Each spacing is small since it is essential to ensure cooling fin containstwo grooves 1,3 which em that .there is no possibility of the electrodes brace the electrode supporting rods 9, 163, respec touching, when the assemblyv is complete,zeither tively, theserods' extending a 'sho'rt'dista'nce bedue vibretionyfoi amp e-or in t e process yontrthe ends-of the cooling fins} The indirectly 30 of mounting the electrode structure on" thepinch h at d t o z; t e; grid and the'anqde 4. of the tube. All these, and .other desiderata are: registered position by insulating. 301- fulfilled bythe arrangements of this invention; example, of mi u i tl th kit 1 In accordance w s invention w p vid siderable rigidity,-'each strip containing five small 352 an electrondischarge tube in which all the 816C- apeftur'es d; b; c, 'd,' e;-in ailing; 'Th insulating t d s are a s mbl d n a si e ri d u t ad p stiipsare arranged-over the top and bottom ofed to be mounted complete on the Pinch of the the electrode supporting rods 9, l0 whereby the lJulieindirectly heated cathode .is supported between Another feature of the invention is an electron t t central 1 1 c: t grid electrode being 40 discharge tube including n emissive Cathode supported between the two holes (2, e, on one side 40 d wo or more other electrodes provided with of the center and the anode between the two holes Cooling fi s a Supported y, all the 9186- a, b, on the other side of the center. The strips des being pported and registered n position H are held firmly in position by small collars l2, in a rigid u y Structure y insulating meansl3 which are slipped over the ends of the sup- A further feature of the invention is an elecporting rods extending through the strips and 45 tron discharge tube including at least an emisfirmly clinched on to the supporting rods 9, It]. If sive cathode, and two or more other electrodes desired a small washer may be inserted between provided with cooling fins, all the electrodes bethe collar and the strip, and further the collars ing' registered in position and supported between may be arranged on only one of the supporting two rigid insulating end members attached to rods of each electrode, the other being free. A the said cooling fins, to form a complete unitary metal collar may also be provided where the inelectrode structure. directly heated cathode passes through the discs Other features of the invention will be apparat c. ent from the following description and the ap- The ends of the cooling fins 3, 6, remote from pended claims. the electrode portions I, 4, are bent at right angles at their edges, approximately level with the end'of the strips ll, thereby forming two plane portions l4,l5 perpendicular to the cooling fins, which serve to give additional support to the insulating members.

It will be seen that we thereby provide a rigid electrode structure, in which all the electrodes are supported and registered firmly with respect to one another, and this single unit can be mounted as desired in a vacuum tube. In the preferred embodiment the electrode; is

mounted between two rigid supports .16, ll gFig,

2) held by the pinch of the tube 'and secured as by welding to theplane pdlffidns m rror the" coolingfins which are at right angles to, the main cooling fins 3, 6,'a s above referred to.- One of the supports, I6, forms theeonducting! lead" a to the grid electrode and the other-"support, F1,

the conducting lead to the anode. Connectionsare made by suitable flexible connections [8 to the heating element for "the indirectly heated cathode and to the cathodeitselfw For prefere ence the unit is mounted in an inclined position I The advantagesof the-constructioniaccording to this invention are manyu As dllwaChFpOintEfi out the complete electrode beassembled, with the electrodes properly spaced and arranged prior to mounting the arrangement on the pinch of the tube. The construction is simple andv extremely rigid,: is very importantin tubes of this type mwhichthe clearanoebetween the electrodes is normally very Thelarge area ofthe cooling fins 3 and 6 and their-lateral extensions M; 5 provides-emcient cooling so'thatthe electrodes may be'positioned very closely .ade jacent, for example, withina rew millimeters ofeach other, whereby a high" mutual conductance for the tube is obtained Iidesired-iurther cooling may be provided .in' higher power tubes by additional fins arranged "laterally andperpendicular'to the normal: cooling fins and welded thereto;

-What is claimed is: r ,-1. An electron discharge device comprising an enclosing vessel, a unitary assemblytherein in:- eluding a pair of spacedsinsulating members having a plurality of apertures therein, a cathode 'ing apertures for receiving said cathode.

seated at opposite ends in corresponding apertures in said insulating members, a plurality of supports to one side of said cathode and having ends extending through corresponding apertures in said insulating members, means rigidly fixing said supports to said members, and an electrode having a portion in proximity to said cathode and having an outwardly extending portion secured to said supports, and means separate from said supports for mounting said unitary assembly within said vessel.

2. A unitary assembly 'for electron discharge devices, comprising a pair of spaced insulating members having aligned apertures, a cathode seatedat opposite ends in corresponding apertures in said insulating members, a plurality of parallel rodsv having end portions extending Iooselythrough corresponding apertures in said members-collars extending through said apertures for said rods, said collars surrounding and being secured to saiden'd portionsto fasten "said rods to said members, "and an electrode having a portion in'proxi mityto' said cathode and afin' portion secured to said rods. e

3; An electron discharge device comprising an enclosing vessel having'a; stem, a plurality of sup;-

porting members extending 'from' said stem, an anode' having a cylindrical portion and a; fin se-' cured to" one of said supporting members, a'grid electrode having a cylindrical portion within the cylindrical portion; of the anodefand a fin secured toanother of said supporting membersfa cathode within said cylindrical 'grid'portion,.' a plurality of rods separate and spaced from said supporting memberst-mounted on and extending beyond'thel ends of each of said fins; and insulatmg: spacer members disposed. one adjacent each of said fins,-"said 'spacer, members having apertures through which'saidrods pass and hav'--' :4. electron discharge device comprising an electrode." having a cylindricaltportion"and: a flanged fin, a second "electrode having a helical portion; within said cylindricalr'portion 'anda flanged fln'substanti'alh' coplanar with said first flanged finfirod membersmounted on and extending beyondthe ends of saidzfins, a cathode withnixsaidhelical portiomla pair of insulating b di p sed! at o t e Gt fins and seated e mfsaid insulating "members having apertures throughwhich said rodspass, and fastening means engaging saidcinsulatin'g members and said rods for securing said insuIat-A ingrnembersagainstsaid it FRANK D. GOODCI-IILD.

.WILFRID E. 'BENHAM: 

